A Review on Production of Exopolysaccharide and Biofilm in Probiotics Like Lactobacilli and Methods of Analysis

Abstract

Synthesis of exopolysaccharides (EPSs) by lactic acid bacteria is well known and the EPS produced by Lactobacillus has been highly regarded in recent years because of its unique physical and chemical application in the food and pharmaceutical industry. One of the capabilities of probiotics is the use of EPS to form a biofilm produced in tense environments. In this paper after a short description about EPS, the reason for production in bacterial cells, and its biosynthesis pathways; the capability of Lactobacilli for EPS and biofilm formation are reviewed. The chemical composition of EPS, its role in the bacterial life cycle as well as applications for humankind have been studied. Then the important components in biofilm formation are described and variable influencing on biofilm formation (surface, bacterial cell surface, contact time and environmental characteristics) are reviewed. The relationship between EPS and extracellular polymeric precursors as well as the relationship between biofilm formation and EPS production are mentioned. Finally, methods for quantification of carbohydrate (enzymatic, physical, chemical methods), biofilm formation and EPS extraction (Tallon and Bajpai methods) are reviewed and advantages of methods are compared. EPSs produced by probiotics is important due to the application as a thickening agent, emulsifier, heavy metal eliminator, and drug delivery carrier. Also, it has been considered for its anti-cancer, anti-viral, and cholesterol-lowering properties. So forming biofilm by some probiotics in simple and mixed culture are discussed, the relationship between EPS and biofilm production are discussed. When probiotics produce biofilm, they can be more tolerated in the processing of food production and in the gastrointestinal tract. So the efficacy of probiotic transfer may increase by a self-protection potency without any required encapsulation processing, solvent residue, time and energy consumption, etc. Also, identification and measurement methods are reviewed and compared.